Remember kids, this may
void your warrenty. Is also a federal offence to
tamper with catalytic converters
Downpipe installation on a Subaru WRX
Disclaimer:
Perform this installation at your own risk. We do not assume any responsibility whatsoever for any damages of any kind resulting from any information printed in this article. This article was created as a supplementary resource and should not be used as the lone source of information on this topic. We recommend that you seek the advice of a trained professional. This is simply a guide to show users how we accomplished our own installations.
A few tips for installation:
1. Make sure the vehicle has had sufficient time to cool down. We allowed our WRX to cool off for 3 hours with the hood up and it was still very warm to the touch!
2. Gather all tools you'll need before you begin.
3. Spray all bolts with a lubricant such as LiquidWrench or WD40 and allow to penetrate for about an hour.
5. Use protective eye wear. Our tools consisted of a socket set, box end wrenches, an adjustable wrench, wire crimpers and some wire snips.
Step 1:
Remove the heatshield. You'll be amazed at the amount of bolts used to hold on this simple piece of metal. There are 5 on the left side (viewing from the front of the car), one on the back, and two on the right side. After you have all the bolts removed you're going to need some keen geometry skills to get the heat shield out of the engine bay but once you do, the downpipe to turbo connection is easily available. Once the downpipe is exposed look for the bottom heatshield. It connects to the downpipe by one bolt.
Step 2:
Loosen the downpipe. There are only 5 bolts holding the downpipe to the turbo. They are surprisingly easy to get to. Now would also be a good time to remove the O2 sensor from the Downpipe. Reference Step 5's picture for it's location.
Step 3:
Disconnect the remaining hangers. We've used photos of the exhaust out of the car in order to point out where the hangers are in relation to the whole system. Install the new Downpipe by lining up the turbo/ downpipe bolts then securing the hangers. There are 2 hangers for the downpipe shown here. The front one bolts into the tranny. The second rests on a J bracket and is screwed in.
Step 4:
Hooking up the Midpipe. This one is very easy. Simply use the gasket provided by M2 to join the downpipe to the midpipe. Then use the stock rubber hanger and presto!
Step 5:
With the Midpipe in place it's time to relocate the O2 sensor. This step is required since the M2 system has it's cat in the midpipe. Without the O2 sensor plugged in, you can expect to see a check engine light come on. We had to splice the O2 sensor to extend it the 12" or so required to reach the new bung, but have since learned that this step might be unnecessary due to some extra length of O2 wire tied up in the engine bay.
OK this is a combined installation of a Down-pipe and exhaust, dont mind the last few comments. Remember to use some Liquid wrench, the bolts on the downpipe connecting the midpipe can be a pain in the arse. I had to sawzall mine. Trimming of the heatshield may be needed when re-installing, dont cut yourself cuz it can be sharp.